Twenty-eighth Orchid of the Season and Others

All five Piperias (now Platantheras) can be found in Olympic National Park.  We found four of the five when we were there in July, but this one, the fourth we found, was very nearly finished flowering.  In fact, we found only one spike that still had any flowers on it and they were well on their way to oblivion.  The species looks like Platanthera unalascensis, the Alaskan Piperia, but has white instead of green flowers.  The inflorescences grow to 60 cm with numerous 3-4 mm flowers.  At flowering the leaves are usually withered away or starting to wither, a characteristic of all the Platanthera/Piperias.  Known until recently as Piperia candida, it is now classified as Platanthera ephemerantha.

Platanthera ephemerantha

Along with Platanthera ephemerantha candida we found more Platanthera elongata, with its small, faintly fragrant, green flowers and long downward-curved spur.  Like the other Piperias, it seems to be one of the few orchids unaffected by the hot dry summer we've had, though, as is characteristic, the leaves have usually withered away.  These plants tend to grow on exposed hillsides, trailsides, and dry mossy banks, as well as in dry forests.  Platanthera elongata, is the last of the Platanthera/Piperias to bloom, though their blooming seasons overlap and it is possible to see them all in bloom at the same time.  On this trip it was also the most common of the Piperias and seemed to be on every roadside bank.

Platanthera elongata

Note: I've included some older pictures of Platanthera ephemerantha for lack of anything recently taken.

Platanthera ephemerantha

Platanthera ephemerantha, formerly Piperia candida, is another of the five Platnathera/Piperia species we have in the Pacific Northwest.  It closely resembles Platanthera unalascensis except for the fact that its flowers are white instead of green and therefore also more showy.  Both species have small flowers and a much shorter spur or nectary than the more showy Piperias, but this species is not unattractive.  The plant can be quite tall, over 60 cm, but the flowers are only 3-4 mm, more or less densely packed on the flower spike.  Very often the leaves are withering or have disappeared by the time the plant blooms.  It seems to prefer open dry woodlands and roadside banks.

Washington's Five Piperias

Here in the Pacific Northwest and up into Canada there are five Piperia species, though two others have been reported periodically from Washington and Oregon, but without verification.  The Piperias have been separated from the genera Habenaria and Platanthera (more recently they have been recombined with Platanthera).  They share a tuber-like root, very slender spikes and flowers with similar-looking lips and petals.  The leaves of all these species almost always wither around the time of flowering, so that the flower spikes appear as leafless stems.  The two unverified species are Piperia leptopetala, the Lace Orchid, and Piperia michaelii, Michael's Piperia.  The five species known to grow in our area are as follows:

Platanthera (Piperia) unalascensis, the Alaskan Piperia.
This is the most common of the five Piperias and has the widest range, growing from Alaska south to California and east across southern Canada and the northern United States into the Great Lakes region.  It is also, in my opinion, the least attractive of the five species, with small green or greenish-yellow flowers.  It can grow in large clumps and to a height of over 80 cm, and the flowers, though numerous are less than 1 cm in size and have a tiny spur that is barely visible.

 

There is a dwarf form of this species, forma olympica, that grows only in one location in the Olympic Mountains (these last two pictures show this form).

Platanthera ephemerantha (Piperia candida), the Slender White Piperia.
Piperia candida has been recently separated from Piperia unalascensis and the flower color is the most obvious difference.  Its flowers are white instead of green, though there are also differences in the shape of the spur and in the fact that this species has a day-time though faint fragrance.  In plant size, flower count, bloom time and habitat it is is like the Alaskan Piperia, but in our experience is somewhat more rare than its green cousin.

Platanthera (Piperia) elegans, the Elegant Piperia.
The Elegant Piperia is rightly named and the most attractive of the five species.  The plants can be very large, over 80 cm with numerous, tightly packed flowers that are somewhat larger than those of the previous two species, but still smaller than 1 cm.  It, too, has a faint fragrance but a much longer spur, that is nearly 1 cm.  Is is quite easily identifiable and cannot really be mistaken for any of the other species.  The tall plants with their white, long-spurred flowers are distinctive

Platanthera (Piperia) elongata, the Long-spurred Piperia.
This and the following species are quite easily confused.  In plant size, number of flowers, size of flowers and length of spurs they are very similar.  The plants are 60 cm or less and they have numerous flowers more or less crowded on the stems.  This species, however, has flowers that are dark green with a spur that curves downward, often paralleling the stem.  The flowers, though small and less than 1 cm in size are quite attractive with their long, 1.5 cm spurs.

Platanthera (Piperia) transversa, the Flat-spurred Piperia.
The Flat-spurred Piperia is named not for the shape of of the spur but for its position, one of the distinguishing characteristics.  The flowers are the same size as Piperia elongata and the spurs the same length, but the spur is held horizontally and in some cases even curves upward a bit.  That and the white flowers with a green or yellowish green mid-vein to each of the segments separates this from the Long-spurred Piperia.